GLASS BREAKAGE DETECTOR:
This is an INPUT DEVICE which is triggered by either the sound of breaking glass or the sudden impact of something against a pane of glass. WINDOW BUGS, FOIL, AUDIO GLASS BREAK SENSORS all fall into this "family" of INPUT DEVICES.
GROUND FAULT or GROUND FAULT TROUBLE: A condition in which an alarm system references a structure's common electrical ground plane. This can be caused by a wire to an INPUT or OUTPUT DEVICE that is "pinched" or been abraded so as to contact the metal back box (or conduit). In the latter instance, the wire can become abraded (or skinned) during the installation process exposing the bared conductor(s). In some systems a fault condition can be artificially generated when the wiring is incorrectly terminated or when multiple power supplies are involved. Another common cause is water ingress at a field device such as a ceiling mounted smoke or heat detector. Ground faults are not difficult to pinpoint but often present a challenge to the servicing technician when more than one are present on a system or if the fault is intermittent (as may be the case for water ingress). For information on how to solve a ground fault trouble, you might want to visit our TIPS page.